WO1982003714A1

WO1982003714A1 - Signalling device for a machine,indicating the need for a maintainance service

Info

Publication number: WO1982003714A1
Application number: PCT/EP1982/000081
Authority: WO
Inventors: Ag Bmw
Original assignee: Bourauel Fritz; Weishaupt Walter
Priority date: 1981-04-10
Filing date: 1982-04-08
Publication date: 1982-10-28
Also published as: JPS58500539A; EP0062868B1; DE3114689A1; JPH0312696B2; US4551703A; EP0062868B2; DE3277651D1; EP0062868A1; DE3114689C2

Abstract

The signalling device provides a signal indicating the need for a maintainance service when a limit value of a given magnitude is reached. This magnitude is function of the total number of revolutions of an output shaft or of any other rotary part and optionally of one or a plurality of additional operation parameters.

Description

Service interval indicator for engines

The invention relates to a service interval display device for engines that drive other devices via an output shaft, with a signal generator that delivers a signal when a parameter limit value is reached. The engines can e.g. B. internal combustion engines or electric motors. As driven devices such. B. compressors, heat pumps, motor vehicles or hydraulic units in question.

In a known display device of this type, the total number of operating hours is taken into account as a parameter. However, the actual load on the engine is not taken into account. The result of this is that service is often carried out much too early, since the parameter limit value must be dimensioned such that service is carried out in good time even under extreme loads on the engine. Otherwise the service would be carried out too late for extremely stressed engines. For the majority of engine users, this means unnecessarily high operating costs. Economically, it is also disadvantageous, since parts are often replaced as a precaution, which would continue to work flawlessly for a certain operating period and could therefore remain in the engine or the driven devices. The invention has for its object to provide a display device of the type mentioned, which usually indicates a necessary service when it is actually required.

The solution to this problem is that the parameter is dependent on the total number of revolutions of the output shaft or another rotating part.

The service interval can be adapted to the actual requirements by the invention. With a gentle mode of operation, for example by avoiding extreme speeds, the service interval can be extended longer than with an exclusive consideration of the operating hours or with a predominantly extreme load on the engine.

It is possible to use the total number of revolutions of the output shaft as the parameter. In contrast, there is an even further improved adaptation of the signal supplied by the signal generator to the actual need for service if the parameter is composed of the actual total number of revolutions and an additional portion which is formed in accordance with the load on the engine.

The load can be taken into account in various ways. So it is possible to add the additional portion additively according to this load. In contrast, the additional portion can be taken into account particularly easily in terms of circuitry and with great accuracy by multiplying the load in the form of a factor with which the number of revolutions is applied before it is registered. Such multiplication can be done, for example, by introducing prescenders are made, which are supplied with pulses corresponding to the revolutions and which are switched, for example, when the engine is subjected to extreme loads. so that the speed is evaluated according to the load.

This factor can come into play in different ways. For example, it is possible for the factor to be effective or ineffective only when there is an extreme value of an operating parameter. The factor can be as long as be switched off, as the extreme value is, or until a predetermined number of revolutions is reached.

However, the factor can only be effective or ineffective as long as the value of the operating parameter is above or below a predetermined limit value. In this case the factor also only becomes effective during an extreme load on the engine, whereas it does not appear under a "normal" load. As a result, the computational effort can also be kept low here.

A factor that is only effective with an extreme value of an operating parameter can be constant or change according to the value of the operating parameter. While a constant factor can be taken into account with little computing effort, a changing factor offers the advantage that the surcharge given by the factor can be selected according to the actual requirements and the service interval can be optimally specified.

A further optimization of the service interval can be achieved in that the factor is composed of several parts: which are assigned to different operating parameters. Because an excessive load on the engine at extreme values of different para meter, the service interval can be selected exactly by taking all or a large part of these parameters into account.

The load criterion can be the speed of the output shaft itself, the temperature of an operating fluid such as cooling water or engine oil, and / or the rate of energy consumption. For all criteria, donors are usually already provided anyway, so that the inclusion of this criterion is possible with little expenditure on equipment.

In the context of the invention, a further advantageous measure can be to subdivide the parameter limit value into equal intervals and to assign a control light to each of these intervals, which goes out at the end of the interval. By dividing the intervals, a particularly stressful mode of operation can be recognized even before the limit value is reached, since the indicator light for the associated interval then goes out noticeably faster.

It will often be sufficient to switch on the warning lights only before switching on or starting the engine and to switch them off immediately afterwards. With each switch-on process, the operator receives information about the remaining operating period and, on the other hand, is not disturbed by the indicator lights during operation.

In addition to the indicator lights, if the service is not carried out, they can be reached when they are reached. of the characteristic limit value formed in the device according to the invention, alone or in connection with a load-dependent evaluation from the number of revolutions of the output shaft, a warning display, e.g. B. in the form of a single warning light with different colors from the indicator lights be switched on. Furthermore, additional warning lights can be switched on permanently after the same overdraft intervals. These intervals can also be determined by evaluating the number of revolutions of the output shaft and can be half the size of the parameter interval. With increasing urgency, an indication of the need for maintenance is given.

At the same time with or instead of a warning display, a neon sign can be switched on permanently, thus also clearly indicating the need for service.

In order to ensure that service is indicated even in the case of an extremely low annual mode of operation, a target time can be assigned to the parameter limit value, after which the signal also appears; the target time can be the actual time since the last service. In such cases, the service is required due to signs of aging, such as the operating fluids used; Apparitions that are not important in a "normal" mode of operation. In this case, too, the service interval is optimized and a service is indicated when this is necessary.

The target time can be divided into a number of target time intervals equal to the number of characteristic variable intervals. The switching status of the indicator lights is also changed if the respective target time interval has expired before the corresponding parameter interval. A corresponding choice of the parameter limit value and the target time ensures that the switching status of the indicator lights is changed by the expiry of the target time intervals only in the cases where the reversal total is below average. The total number of revolutions therefore usually remains decisive for the display device. In this way it can be achieved that, in addition to the engines with at least average operating time, a reference is also made to the required service for the engines, which are used relatively little.

Since the service required when the target time expires is generally different from the service required when the parameter limit is reached. B. only an oil service may be required - a luminescent lettering can be switched on when the target time has expired, which is different from the luminescent lettering switched on when the parameter limit value is reached. This distinction can be achieved, for example, with the illuminated letters "oil service" for the parameter limit value and "inspection" after the target time.

As when the parameter limit value is reached, a warning display can also be switched on permanently if the target time is exceeded.

This warning display can consist of the warning lights for the overdraft intervals. For this purpose, the overdraft intervals are assigned the same overdraft time intervals, which are approximately half as long as the target time intervals and when these expire before the associated overdraft interval expires, these warning lights are also switched on. This halving of the time intervals after the target time has elapsed results in the warning function being amplified much more quickly, even in the case of less used engines. In most cases, maintenance is carried out long before the target time expires when the parameter limit value is reached. As an example, a period of eleven months applies to the application of an internal combustion engine of a motor vehicle for the target time and a value of 2 · 10 ⁷ revolutions for the parameter limit value. In this case, maintenance consists of e.g. B. in an oil service. After about twice the parameter limit value, the so-called maximum value, extensive maintenance is usually required. This maintenance corresponds approximately to the maintenance after the target time has expired. In order to indicate such maintenance with the aid of the display device particularly clearly, after carrying out maintenance after reaching the characteristic limit value, the difference between the present characteristic value and a maximum value that is about twice as large as the limit value is divided into equal difference intervals, the number of which is equal to the number of parameter intervals and which replace them. Immediately after such maintenance has been carried out, the switching status of the indicator lights is determined by the elapsed time, which is taken into account unchanged. In the further course, the switching status of the indicator lights will then again often be determined by the total number of revolutions.

As with the parameter limit value and after the target time has elapsed, the warning display can also be switched on for the maximum value. In this case too, the driver then receives precise information about how much he has exceeded the maximum value.

In addition, when the maximum value is reached, the same illuminated sign can be switched on as when the target time has expired. In this way it is taken into account that the maintenance to be carried out in both cases is largely the same. The invention is further explained using an exemplary embodiment shown in the drawing. The drawing shows a service interval display device for an internal combustion engine, in which the number of revolutions of the output shaft is evaluated according to the load.

Pulses corresponding to the number of revolutions of an output shaft enter the switching arrangement. These reach a memory 2 via a type encoder 1, with which different types of engines or driven devices are taken into account, via prescaler V ₁ to V _5. The prescaler V ₁ takes into account an extreme load on the internal combustion engine as a result of a low temperature of an operating fluid, for example the engine oil. For this purpose, the output signal of an engine oil temperature sensor, not shown, is fed to a comparator 3, which is at a predetermined temperature of, for. B. 320 K provides an output signal and then turns off the prescaler V ₁ . This means that the prescaler V ₁ is effective above this temperature and then reduces the number of pulses passed on to the prescaler V ₂ .

The prescaler V ₂ takes into account the fuel consumption rate and is switched on as long as this rate is below a predetermined limit.

The prescaler V ₃ and V ₄ take into account a load on the internal combustion engine based on the speed of the output shaft or a rotating part itself. The prescaler Vo is switched on until a predetermined limit speed of, for. B. 5,000 / min. has not yet been reached. The prescaler Vii is effective until the speed a second, higher limit of z. B. 6,000 / min. exceeds. The preselectors V ₃ and V ₄ thus take into account digital speeds of different heights. The switch-off duration of the prescaler V ₁ to V ₄ can be selected as long as the extreme load of the vehicle engine taken into account persists. However, it can also be selected for a predetermined time or number of revolutions. Timers or revolution pulse counters (not shown), which determine the switch-off duration of the prescaler, can serve for this purpose.

The prescaler V ₅ delivers for predetermined total revolutions of z. B. 4 · 10 ⁶ each have an output signal. This number corresponds exactly to the actual total number of revolutions, provided that only extreme loads on the internal combustion engine have occurred and therefore all prescaler V ₁ to V _{4 were} ineffective. In the normal case, however, this number is smaller than the actual total number of revolutions, according to the loading factor factors given by the preselectors V ₁ to V ₄ . The ratio of the calculated with the help of the prescaler V ₁ to V ₄ and the actual total number is greater, the lower the load on the internal combustion engine.

The output pulses of the prescaler V ₅ reach the memory 2, which is designed as a shift register and which switches on its outputs 4 to 8 and 10 to 12 at intervals of 4 × 10 ⁶ revolutions, ie the total number obtained from the actual number by calculation.

The outputs 4 to 8 are via inverters 14 to 18 with z. B. green LEDs 24 to 28, which in turn go out at a distance from these total revolutions. Depending on the mode of operation and the other conditions, the LEDs remain switched on for the intervals of 4.10 ⁶ revolutions, and in relation to an operating mode with extreme load on the internal combustion engine, the more gently the internal combustion engine is operated. The output 8 of the memory 2 is also connected via an OR gate 34 to a light emitting diode 29 which, for. B. has a yellow color. The LED 29 is also controlled via a timer 33 and the OR gate 34, which after an operating time of z. B. 11 months after performing the last maintenance. The light-emitting diode 29, which lights up permanently at 20.10 ⁶ revolutions corresponding to five output pulses of the prescaler V ₅ , is therefore also switched on after the set time determined by the timer 33 and in this case also draws attention to the fact that service is required.

More, e.g. B. red light-emitting diodes 30 to 32 are directly connected to the outputs 10 to 12 of the memory 2 and increase the urgency of maintenance to be carried out.

Instead of only digitally acting advantages V ₅ to V4, the load on the internal combustion engine can also be taken into account analogously. For this purpose, computing elements can be provided which multiply the incoming revolution impulses by a factor which is variable in accordance with the operating parameter taken into account or form the sum of such variable factors in the case of several operating parameters.

In order to avoid unnecessarily affecting the driver by the display device, at least the light-emitting diodes 24 to 28 can be connected in series with an oil pressure switch 35 or the like. If the associated target path distances have not yet expired, the LEDs light up until the operating criterion of the internal combustion engine (here engine oil pressure) is met. By correspondingly expanding the switching arrangement shown, the overdraft intervals assigned to the light-emitting diodes 30 to 32 can be halved compared to the intervals for the light-emitting diodes 24 to 29. For this purpose, a factor 2 prescaler can be switched on between prescaler V4 and prescaler V ₅ , which is effective until output 8 of memory 2 is switched on. To the LEDs 24 to. 28 off or simultaneously switching off the light emitting diode 28, the light emitting diode 29 requires a total of ten pulses, while only three impulses of the prescaler V _{5 are} required to switch on the light emitting diodes 30 to 32.

In addition to the light-emitting diode 29, a time interval can also be assigned to the light-emitting diodes 24 to 28 and 30 to 32 by appropriate wiring. Instead of the timer 33, a memory corresponding to the memory 2 is then to be provided, which has the same number of outputs and which is clocked by a timer. Each output of this memory, like the outputs of the memory 2, is connected to the light-emitting diodes 24 to 32 via additional OR gates to be provided corresponding to the OR gate 34. By means of an analog prescaler circuit it can also be achieved here that the overdraft time intervals then assigned to the light-emitting diodes 30 to 32 are halved compared to the target time intervals for the light-emitting diodes 24 to 28 (or 29).

Depending on the desired application, it is also possible to take into account a load on an engine which is noticeable by a reduction in speed or a relative relief which can be recognized by an increase in the speed. This is the case, for example, with an engine for a compressor in front. The prescaler V ₃ and V _{4 can also be} provided for this. In contrast to the described application of the internal combustion engine, for. B. for a motor vehicle, the preselectors V ₃ and V _{4 are} deactivated at a relatively low speed (high load). At medium speed (normal load), only one of the two prescenders is activated. At higher speeds (low load) both prescenders Vo and V _{4 are} effective. In this way it is achieved that the rated speed is inversely related to the actual speed.

For reasons of clarity, we do not present extensions to the switching arrangement that can be used to distinguish between two types of service. Such a switching arrangement, shown in patent application P 31 04 197.3, contains a further memory which, after performing a first service, is switched to the LEDs 24 to 32 instead of the memory 2. It receives its cycle at intervals of equal difference intervals, which are formed by dividing the difference between the number of revolutions available at the first service and a maximum revolutions value twice as large as the limit value. This extension can also be connected to different neon signs which indicate the first service when the number of revolutions limit is reached and the second service when the maximum number of revolutions is reached or when the target time has expired.

Claims

Claims:

1. Service interval display device for engines that drive other devices via an output shaft, with a signal generator that delivers a signal when a characteristic limit value is reached, characterized in that the characteristic variable is the total number of revolutions of the output shaft or another rotating part is dependent.

2. Apparatus according to claim 1, characterized in that the parameter is composed of the actual total number of revolutions and an additional portion, which is formed according to the load on the engine.

3- Display device according to claim 1, characterized in that the load is taken into account by a factor with which the number of revolutions of the output shaft is applied before it is registered.

4. Display device according to claim 3, characterized in that the factor is effective only at an extreme value of an operating parameter.

5. Display device according to claim 4, characterized in that the factor is only effective as long as the value of the operating parameter is above or below a predetermined limit.

6. Display device according to claim 5, characterized in that the factor is constant.

7. Display device according to claim 5, characterized in that the value of the factor changes according to the value of the operating parameter.

8. Display device according to one of claims 3 to 7, characterized 'in that the factor is composed of several parts which are assigned to different operating parameters.

9. Display device according to one of claims 2 to 8, characterized in that the speed of the output shaft itself serves as a criterion of the load.

10. Display device according to one of claims 2 to 9, characterized in that the temperature of an operating fluid is used as the criterion of the load.

11. Display device according to claim 10, characterized in that the operating liquid is the cooling water.

12. Display device according to claim 10, characterized in that the operating fluid is the engine oil.

13. Display device according to one of claims 2 to 12, characterized in that the energy consumption rate serves as the criterion of the load.

14. Display device according to one of claims 1 to 13, characterized in that the limit value is divided into equal intervals and that each of these intervals is assigned a control lamp (24 to 28) which goes out at the end of the interval.

15. Display device according to claim 14, characterized in that the indicator lights go out immediately after switching on the engine.

16. Display device according to claim 14 or 15, characterized in that simultaneously with the extinguishing of the indicator lamp. (24) a fluorescent sign ("oil service") is permanently switched on for the last parameter interval.

17. Display device according to one of claims 14 to 16, characterized in that a warning display is switched on permanently when the parameter limit value is exceeded.

18. Display device according to claim 5, characterized in that the warning indicator is a warning light (29) with the control lights (24-28) different color.

19. Display device according to claim 18, characterized in that the warning light (29) and further warning lights (30 - 32) are switched on successively after the same overdraft intervals.

20. Display device according to claim 19, characterized in that the overdraft intervals are approximately half as large as the parameter intervals.

21. Display device according to one of claims 14 to 20, characterized in that a target time is assigned to the parameter limit value, which is divided into a number of target time intervals equal to the number of parameter parameter intervals and that the switching state of the indicator lights (24-28) is also changed if the respective target time interval has expired before the corresponding parameter interval.

22. Display device according to one of claims 17 to 21, characterized in that the warning display is switched on permanently even when the target time is exceeded.

23. Display device according to one of claims 16 to 22, characterized in that a fluorescent sign ("inspection") is switched on when the target time has expired, which is different from the illuminated sign switched on after the last core size interval ("oil service").

24. Display device according to one of claims 19 to 23, characterized in that the same overdraft time intervals are also assigned to the overdraft intervals, which are approximately half as large as the target time intervals and when they expire before the associated overdraft interval also the warning lights (29 - 32) can be switched on.

25. Display device according to one of claims 1 to 24, characterized in that after carrying out maintenance before the expiry of the target time, the difference of the then present parameter value from a maximum value which is about twice as large as the limit value is divided into equal difference intervals, the Number is equal to the number of parameter intervals and which take their place.

26. Display device according to claim 25, characterized in that when the maximum value is reached the warning display is switched on as when the parameter limit value is reached.

27. Display device according to claim 26, characterized in that when the maximum value expires, the same illuminated sign ("inspection") is switched on when the target time has expired.